Re: plpgsql plugin - stmt_beg/end is not called for top level blockof statements - Mailing list pgsql-hackers
| From | Pavel Stehule |
|---|---|
| Subject | Re: plpgsql plugin - stmt_beg/end is not called for top level blockof statements |
| Date | |
| Msg-id | CAFj8pRDTKbnbKFu3KRtLq772ZR18JM6Yg6a5AXYkEH_rfdmSOA@mail.gmail.com Whole thread Raw |
| In response to | Re: plpgsql plugin - stmt_beg/end is not called for top level blockof statements (Michael Paquier <michael@paquier.xyz>) |
| Responses |
Re: plpgsql plugin - stmt_beg/end is not called for top level blockof statements
|
| List | pgsql-hackers |
pá 28. 12. 2018 v 3:26 odesílatel Michael Paquier <michael@paquier.xyz> napsal:
On Wed, Dec 26, 2018 at 07:02:04AM +0100, Pavel Stehule wrote:
> is called two times, what is not expected, if you don't know some about
> this inconsistency.
>
> So it is reason, why I don't think so current behave is correct. On second
> hand, the impact is very small - only few extensions uses plpgsql plugin
> API, and workaround is not hard. So I can live with current state if nobody
> see this issue (sure - it is minor issue).
Hm. Using the following functions based on the code of above, I can
see the following numbers if I place some trackers (elog(WARNING)
entries) at the beginning of each callback part of plpgsql_check.c to
measure how many times a callback is done:
CREATE OR REPLACE FUNCTION public.f2()
RETURNS void
LANGUAGE plpgsql
AS $$
DECLARE x int;
BEGIN
x := 2;
RETURN;
END;
$$;
CREATE OR REPLACE FUNCTION public.f3()
RETURNS void
LANGUAGE plpgsql
AS $$
DECLARE x int;
BEGIN
BEGIN
x := 3;
RETURN;
END;
END
$$;
On HEAD, for plpgsql_check_function_tb('f2()'):
- stmt_beg is called 4 times.
- stmt_end is called 3 times.
- func_setup is called 2 times.
- func_beg is called 2 times.
- func_end is called 2 times.
For plpgsql_check_function_tb('f3()'):
- stmt_beg is called 3 times.
- stmt_end is called 3 times.
- func_setup is called 1 time.
- func_beg is called 1 time.
- func_end is called 2 times.
So based on the previous example f2 gets over f3 one extra stmt_beg,
one extra func_beg and one extra func_setup.
With patched HEAD, I got for f2:
- stmt_beg is called 6 times.
- stmt_end is called 5 times.
- func_setup is called 2 times.
- func_beg is called 2 times.
- func_end is called 2 times.
And for f3:
- stmt_beg is called 6 times.
- stmt_end is called 5 times.
- func_setup is called 2 times.
- func_beg is called 2 times.
- func_end is called 2 times.
--
Michael
These numbers are little bit strange - maybe due using plpgsql_check. I wrote simple extension (see attachment)
CREATE OR REPLACE FUNCTION public.f2()
RETURNS void
LANGUAGE plpgsql
1 AS $function$
2 DECLARE x int;
3 BEGIN
4 x := 2;
5 RETURN;
6 END;
7 $function$
RETURNS void
LANGUAGE plpgsql
1 AS $function$
2 DECLARE x int;
3 BEGIN
4 x := 2;
5 RETURN;
6 END;
7 $function$
CREATE OR REPLACE FUNCTION public.f3()
RETURNS void
LANGUAGE plpgsql
1 AS $function$
2 DECLARE x int;
3 BEGIN
4 BEGIN
5 x := 3;
6 RETURN;
7 END;
8 END
9 $function$
RETURNS void
LANGUAGE plpgsql
1 AS $function$
2 DECLARE x int;
3 BEGIN
4 BEGIN
5 x := 3;
6 RETURN;
7 END;
8 END
9 $function$
load 'simple';
select f2();
postgres=# select f2();
NOTICE: func setup: "f2()"
NOTICE: func beg: "f2()"
NOTICE: stmt beg - ln: 4
NOTICE: stmt end - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: func end: "f2()"
NOTICE: func setup: "f2()"
NOTICE: func beg: "f2()"
NOTICE: stmt beg - ln: 4
NOTICE: stmt end - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: func end: "f2()"
NOTICE: func setup: "f3()"
NOTICE: func beg: "f3()"
NOTICE: stmt beg - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: stmt beg - ln: 6
NOTICE: stmt end - ln: 6
NOTICE: stmt end - ln: 4
NOTICE: func end: "f3()"
NOTICE: func beg: "f3()"
NOTICE: stmt beg - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: stmt beg - ln: 6
NOTICE: stmt end - ln: 6
NOTICE: stmt end - ln: 4
NOTICE: func end: "f3()"
patched
postgres=# select f2();
NOTICE: func setup: "f2()"
NOTICE: func beg: "f2()"
NOTICE: stmt beg - ln: 3
NOTICE: stmt beg - ln: 4
NOTICE: stmt end - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: stmt end - ln: 3
NOTICE: func end: "f2()"
NOTICE: func setup: "f2()"
NOTICE: func beg: "f2()"
NOTICE: stmt beg - ln: 3
NOTICE: stmt beg - ln: 4
NOTICE: stmt end - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: stmt end - ln: 3
NOTICE: func end: "f2()"
postgres=# select f3();
NOTICE: func setup: "f3()"
NOTICE: func beg: "f3()"
NOTICE: stmt beg - ln: 3
NOTICE: stmt beg - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: stmt beg - ln: 6
NOTICE: stmt end - ln: 6
NOTICE: stmt end - ln: 4
NOTICE: stmt end - ln: 3
NOTICE: func end: "f3()"
NOTICE: func setup: "f3()"
NOTICE: func beg: "f3()"
NOTICE: stmt beg - ln: 3
NOTICE: stmt beg - ln: 4
NOTICE: stmt beg - ln: 5
NOTICE: stmt end - ln: 5
NOTICE: stmt beg - ln: 6
NOTICE: stmt end - ln: 6
NOTICE: stmt end - ln: 4
NOTICE: stmt end - ln: 3
NOTICE: func end: "f3()"
There is only one difference - the plugin routine stmt_begin and stmt_end is called for line 3. Nothing less, nothing more.
Internal evaluation of plpgsql code is same - the change is only for plugin code - one more stmt_beg and stmt_end call - as expected and wanted.
Real impact - now, I have to push my code to func_beg, func_end, stmt_beg, stmt_end. With patch I can push my code just to stmt_beg, stmt_end.
Regards
Pavel
Attachment
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